Electronic devices such as cellular phones, tablets, music players, cameras, etc., often need SIMs and/or memory modules. A SIM stores information regarding the user or user account associated with the device. The information on a SIM is used by a communication network to control and configure access by the device to the network. Currently, the most common form factor of a SIM is a card, and thus a SIM is commonly referred to as a SIM card. A SIM card can be transferred between different devices. SIM cards have become more miniaturized over the years. They may come in a variety of sizes, including a full-size SIM 1st form factor (1FF), a mini-SIM 2nd form-factor (2FF), a micro-SIM 3rd form-factor (3FF), and a nano-SIM 4th form-factor (4FF). The 4FF SIM can be put into adapters for use as a 2FF or 3FF SIM, thus making it backward compatible. On some cellular networks, a mobile device is locked to its carrier SIM card, meaning that the device only works with SIM cards from the specific carrier.
Electronic devices may use memory modules to store photos, videos, music, and documents. A commonly used memory module is a Secure Device (SD) card. Types of SD cards include the standard SD, the miniSD, and the microSD (originally named the TransFlash or TF). The microSD (uSD) is smaller than the standard SD and the mini SDS.